Tablet feeding mechanism



y 1961 H. E. ENGLESON 2,983,374

TABLET FEEDING MECHANISM Filed July 5, 1956 2 Sheets-Sheet 1 y 1961 H. E. ENGLESON 2,983,374

TABLET FEEDING MECHANISM Filed July 5, 1956 2 Sheets-Sheet 2 in which:

' TABLET assume MECHANISM Harry E. Engleson, Chicago, and Stephen V. Klein, Elmhurst, 111., assignors, by mesne assignments, to Crompton 8; Knowles Packaging Corporation, Holyoke,

Mass, a corporation of Massachusetts Filed July 5, 1956, Ser. No. 596,018 7 Claims. (Cl. 209-83) containers may be filled.

It is an object of this invention to provide an improved arrangement of inclined spaced apart rails between which the tablets may be sifted, the rails having hornaloidal or flat surfaces and being dimensioned and spaced to form troughs into which the individual tablets may easily sift without undue jamming.

A further object of this invention is to provide animproved mechanism for feeding tablets from a hopper to' a plurality of chutes wherein a reservoir chamber is provided in which the tablets will move in a plurality of layers within the troughs such that a failure of a first tablet to feed from the bottom layer will not result in a stoppage of tablet feed'from that trough, since other tablets may move over the first and continue to feed into the chutes from another layer; such reservoir chamber may be formed by a first baffle that will pass the tablets in two or more layers from the hopper, and a second baffle that will pass the tablets singly to each of the.

chutes.

Another object is to provide an improved arrangement for feeding disk shaped tablets from a hopper downi wardly into a plurality of inclined chutes andfor expelling malshapen and broken tablets and pieces thereof upwardly from the rear of the hopper; an upwardly moving -belt will be provided at the bottom of the chutes such by the malshapen and broken tablets while the malshapen and broken tablets clinging to the belt may be crushed between the baffle and the belt and thence be ejected under the bafide.

A more complete understanding of the present invention, its mode of operation and its advantages, may be gathered from further reading of this specification, together with an inspection of the accompanying drawings Fig. 1 is a vertical section of a part of a packaging machine including the tablet feeding mechanism as taught 1 by this invention;

(Fig. 2 is a pla'n view alongthe inclined plane 22 of Fig; 3 is an enlarged fragmentarysection -along the 2,983,374 Patented May 9, 1961 F ice Fig; 5 is an enlarged fragmentary section along thE plane 5-5 of Fig. 1; and Y Figs. 6, 7, 8 and 9 are similar enlarged sections taken transversely through a pair of adjacentrails of the packaging machine .and illustrating the manner in which the tablets will sift into the trough between the rails.

The tablet feeding mechanism of this invention constitutes a part of a machine for filling containers with p the tablets, which machine is further described in a copending patent application Serial No. 592,293, filed June 19, 1956, now Patent No. 2,876,604. The machine comprises generally a hopper 1 and a plurality of parallel inclined rails 2 spaced apart such that a narrow slot or trough 3-is formedbetween each adjacent pair of rails 2.

The rails and troughs are arranged beneath the hopper 1 to form a bottom thereof, and extend downwardly at an incline therefrom, as shown in Fig. 1. A movable belt '4 is positioned beneath the-rails 2 to form a bottom for the troughs 3. A stationary support plate 5, Fig. 1, is positioned to support the upper reach of the belt 4 and to hold the belt in close proximity with the rails 2. A pair of rollers 6 and 7 extend transversely across the chutes and support the belt 4. The roller or pulley 6 is drivingly 'coupled to a drive shaft 8, Fig. 1, by means such as a pair of sprockets 9 and 10 and a drive chain 11. The belt 4 is thus driven clockwise around the rollers 6 and 7 (as illustrated in Fig. 1) such that the upperreach thereof formingthe bottom surface of the troughs 3 will move continuously upwardly along the inclined troughs.

The hopper 1 may be filled with tablets or pills 12 to a level 13 such as shown in Fig. 1. The tablets thence sift or drop into the troughs 3 which are dimensioned so narrow as to preclude the possibility of a tablet entering a trough in any position except on edge with the circumferential surface thereof engageable with the belt 4. Since the rails 2 and the troughs 3 are inclined, the tablets will tend to roll downwardly therealong and ultimately the tablets will roll in single file into each of a plurality of ined on a shaft 18 and carries thereon a cam engaging part or cam roller 19, Fig. 1,.such that the arm 17 will be oscillated by the cam 15 as the drive shaft 8 is rotated. A similar arm 20 is pivoted about a point 21 and carries a cam engaging roller 22 which is engaged with the cam 16 and thereby oscillates with movement of the drive shaft 8. The arms 17 and 20 being driven from separate cams 15 and 16 will reciprocate oppositely as the drive shaft 8 turns. Each pivotal arm '17 and 20 has an upward extension 23 and 23. A pair of rigid members extend transversely across the machine and the rails 2. Alternate rails 2 extend upwardly and are rigidly attached to the transverse member 24; while the remaining rails extend upwardly a lesser distance and are rigidly attached to the transverse member 25. The members 24 and 25 are drivingly coupled to'the upward extensions 23 and 23 of the rock arms 17 and 20 by a toggle arrangement which includes pivotal shafts 26 and 27, respectively.

'Thus, as the drive shaft 8 is rotated, the rock arms 17 and 20 and the respective cross members 24 and 25 are oscillated in synchronism such that when one member moves upwardly, the other member moves downwardly. Since alternate ails 2 are attached to the respective transverse members, the rails will reciprocate axially with'e'ach rail moving in a directionopposite to that of the rails adjacent thereto. I

" or fiat surfaces.

Each rail 2 is formed to have a plurality of homaloidal Two of the surfaces 25 and 39 are vertical and constitute opposite sides of each rail 2. An

[inclined surface Ill constitutes the top of the rail. .Two

bevel su'rfacesSZ. and 33 are formed alongopposite sides ,of the inclined topsur face 31 and. between .that surface and'the vertical surfaces 29 and 30, respectively.

Since the alternate rails are in opposed oscillatiomthe tablets 12 contained in the hopper will be agitated and caused to sift into the troughs 3. Figs. 6, 7, 8 and 9 illustrate the configuration and dimensioning of a representative pair of adjacent rails 2, and certain representative tablets 12 are shown in the process of sifting down wardly into the trough 3 therebetween. .If a tablet. comes to rest at themouth of the trough, as shown by 12a, Fig. 6, .the reciprocation of the rails 2 in opposite directions will tendto rotate the tablet about an axis suchv as 28 and the tablet will thereby be turned fiat-wise with respect to the troughs 3.

When a tablet 12 rotates somewhat from its transverse position shown as lZain Fig. 6, it may assume a position .such as 12b in Fig. 7, wherein an edge of the tablet tends to rest against the bevel surface 33. Since the bevel surfaces 32 and 33 are rather steeply inclined, the tablet is unstable in position 1212', and will slide along the bevel surface turning itself in an edge position and thence drop downwardly, as shown by the tablet in Fig. 7 at 12c. It is conceivable that the tablet in position l2a,- Fig. 6, bridged across themouth of the trough 3, may. be turned by the opposed oscillation of the rails 2 and may thence assume a, position such as 12d shown in Fig. 8. The position 12d is likewise an unstable position such that the tablet 12 will slide downwardly on edge between the rails 2 and assume the position 12c.

Fig. 9 illustrates the dimensioning of the rails and the spacing therebetween such that the mouth of the. trough 3 between an edge or corner 34 of a first rail 2. and an edge or corner 35'ofan adjacent rail 2 is slightly more than the diameter ofa tablet 12. Therefore, a tablet which may assume a position. 12a, is too small to span or bridge the distance between the top surface 3110f both adjacent rails forming the trough 3. Asshown in position i2e,-the periphery of'the tablet liesagainst the steeply inclined bevel surface 32. and therefore, as the rails'are oscillated, the tablet will tend to slide down wardly along this surface 32. rotating in a clockwise direction, as viewed in Fig. 9, andultimately dropping on edgeinto the trough 3 as in position. 12c. It may be appreciatedfrom Fig. 9 that if the tablet were positioned slightly to the right of that shown-in- 12c, then the tablet would rest upon the edge or corner 35, but

the opposite side thereof would fail to engage the corner 34, and, therefore, would slide downthe steeply'inclined bevel surface 33 ultimately to assume the position 120 between rails 2.

Figs. 6, 7, 8 and 9-show only two tablets associated with each adjacent pair of rails 2--one tablet within the trough 3 and another at the mouth of-tlie trough. In actual practice, the hopper 1 would be heaped high with tablets and, thus, those tablets at the mouths of the various troughs would beurged downwardly by pressure from other tablets above. Indeed, the tablets near the rails 2 would be under pressure from above and would'be in a state of continual agitation. This arrangement has proved very effective in furnishing a ready supply of tablets which may move rapidly down the inclined chutes.

The shaping of the rails 2 with flat or homaloidalsides has been found to reduce the frictional forces between the tablets and the rails. Because thefrictional forces are reduced,.the tablets will-feed more rapidly into-the .troughs' and thence into the inclined chutes, and the surface wear or deterioration of the 'tabletshas been .minimized. Thus, the shapingof the rails-has-proven advantageous in both increasing the rate of feed; and

from either of the two layers.

improving the handling which results in fewer broken or malshapen tablets which must be'rejected.

As may be seen in Figs. 3, 4 and 5, the troughs 3 are deep enough such that the tablets 12 may rest in two layers, one above the other. Fig. l is a vertical section taken longitudinally through a single trough 3 and shows tablets positioned in two layers one above the other in that trou'ghj3. .Since the troughs 3, are inclined, the tablets. will tend to roll to the left, as shown in Figs. 1 and 2. ,A first baffle plate 36 is positioned transversely across the troughs. along one. side of the hopper 1, and a second baffle plate-37 is; positioned transversely across the rails and troughs but spaced downwardly along the rails and troughs-from the position of the first baiiie plate 36. The rear ,of the;hopper contains an inclined plate 38 also extending transversely across the rails and troughs for directing the tablets 12 thereto. Plate 38 extending transversely. acrossthe railsis fitted with close tolerance .to the rails and su'rfacesthereof and includes a plurality of teeth 39 extending downwardly in spaced relationwith the bottom of the troughs 3 and the belt 4, Fig. 5. The distance between the .bottom of each tooth 39. and the belt 4 may be slightly less than one-half of the diameter of a tablet.

The,configurationofthe'firstbaffle plate 36 may be .seen in Fig. 4. Thewbafiie plate 36 likewise fits closely about the top upper surfaces of the rails 2 and has shallow teeth 46 extending slightly into the troughs 3 but spaced fromthebottom surface or. belt 4 by an amount for permitting two. tablets, one above the other, to pass therebetween. Fig. 3. shows the configuration of the second bafile plate37 which likewise fits closely across the rails 2. The bathe plate 37 has teeth 41 extending downwardly into. the troughs to such a distance that only a single tablet at a time is permitted to pass thereunder.

The space. between batfies 36 and 37 constitutes a tablet reservoir 42 wherein the tablets rest in a plurality of layers. .The specific embodiment illustrated in Fig. 1, shows the tablets 12. positioned in two layers, and the tablets are capable. of feeding to the inclined chutes 14 Thus, if the lower layer becomesclogged or jammed, those tablets fromthe upper layer will roll over the lower layer and continue to feed the chutes 14. Ordinarily,,the tablets are disk-shaped and circular and will roll freely downwardly to the left (as shown in Fig; 1) counter to the upward motion of thebeltll. ;However,,if a malshapen or broken tablet sifts into the troughs between the rails 2, that tablet will not roll freely and willtherefore come to rest with a flattened. side against the belt 4. As-the belt 4 moves upwardly, that malshapenor broken tablet will be carried .upwardlytherewith, while whole tablets which have a circular. configuration will ro11 ;over the broken tablet The malshapen belt 4, while the wholetablets will continue to feed'v'the chutes 14.

Amalshapen or broken tablet will be forced downwardly upon the belt 4 by the Weight of other tablets in the hopper 1; and since the malshapen tablet will not roll freely, it will be carried upwardly by the belt 4. Other tabletswhich are circular will roll over and bypass the .malshapen tablet as :they feed to the chute 14. The

broken tablets will tend to work to a side of the trough and under the rails 2 where they may be further broken and crushed as they are moved upwardly on the belt 4. The inclined baflie plate 38' withits teeth 39 extending into each trough will elevate the whole or circular tablets which may be pushed upwardly. When whole tablets come into engagement with the baffle plate 38, they roll upwardly thereon, ultimately to recirculate, in the hopper as part-of the randomly heaped tablets. The teeth 39 of the bafie 38 extend downwardly into spaced relation with, the belt; 4,. Fig. land-being close to the belt 4, will essentially engage anyn-wlro-letablet below f4 and under thebaffle 38.

broken tablets will be expelled to the rear of the maassent letmoving backwardly onthe belt willbe elevated by the teeth 39 and the bathe, plate 38, but a broken tablet ,may become lodged between the belt 4 and the lower extremity of thetooth 39. The broken tabletwill be further crumbled into smaller pieces which will continue to travel rearwardly (to the rightin Fig, l) on the belt Therefore, malshapen or chine by the belt 4, which Will carry them upwardly under the hopper, ultimately dropping the bits of'tablets and debris therefrom, from the rear into a receptacle (not shown) which may be placed below the roller 6.

Changes may be made in the form, construction and arrangement of, the parts without departing from the spirit of the invention or sacrificing any of its advantages,

" and the right is hereby reserved to make all such changes as fall fairly within the scope of the following claims.

The invention is claimed as follows:

1. In a machine for filling containers with tablets, apparatus for feeding the tablets from a hopper to a plurality of chutes, said apparatus comprising a plurality of inclined rails spaced apartfrom each other to provide an inclined troughbetween each adjacent pair ofrails,

said rails forming a bottom part of the hopper andextending downwardly therefrom to the plurality of chutes, the spacement between each adjacent pair of rails being of a dimension to allow only a single file of tablets on edge to pass therebetween, a movable belt positioned at an incline beneath the rails and constituting a bottom of rails at a side of the hopper, a second baffle plate positioned over and extending transversely across the rails 1 at aspaced distance downwardly along the inclined troughs from the firstbaffle plate, each of said baflle -plates having a series of teeth thereon, each tooth ofthe first bafile plate extending downwardly into a corresponding trough to provide a spacement between the tooth and .the movablebelt equal to slightly more than two tablet 'diameters to permit a pair of tablets aligned vertically on edge to pass between the tooth and the belt, each tooth of the second baflle plate extending downwardly into a corresponding trough to provide a spacement between the tooth and the movable belt equal to slightly more than one tablet diameter to permit only a single tablet to pass between the tooth and the belt.

2. In a machine for filling containers with disk-shaped tablets, apparatus for feeding whole tablets from a hopper to a plurality of chutes on a front side of the machine and for expelling malshapen and broken tablets from the rear side thereof, said apparatus comprising a plurality of inclined rails spaced apart from each other to provide an inclined trough between each adjacent pair 'of rails, a movable belt positioned beneath the rails and constituting a bottom for the troughs, said rails and said belt being positioned beneath the hopper forming a bottom thereof and extending downwardly therefrom, a front baffle forming a front side of the hopper, a rear baflle forming a rear side of the hopper, and a means drivingly coupled to the belt for moving the belt upwardly along the incline, both of said baflles having teeth extending into the troughs, each of the teeth of the front bafile being spaced a distance from the belt to permit two tablets to roll thereunder in each of the troughs, each of the teeth of the rear baflle being spaced a distance from the belt to intercept and elevate any whole tablets moving upwardly along the belt and to pass debris and pieces of tablets under the rear baflie whereby the debris and pieces of tablets are expelled from the hopper.

3. In a machine for filling containers with tablets, a

' has, apparatu for feeding the tablets tram said h'o'p- Eper, said-apparatus comprising a plurality of elongated parallel rails spaced apart to define a plurality of juxtaposed troughs, said railsextending at an incline from thehorizontal and forming thebottom of the hopper, an endlessfmovable belt positioned beneath the rails and at the same inclination thereof so that the upper reach thereof forms a bottom for the troughs, the longitudinal axis of the belt paralleling the longitudinal axis of the troughs, means for driving the belt so the upper reach thereof continuously moves upwardly beneath the troughs, each of said rails having a plurality of homaloidal surfaces extending along substantially the entire length thereof-and including a pair of vertical surfaces and at least one upper inclined surface, the adjacent vertical surfaces of adjacent rails being spaced apart a distance less than the longest dimension of each tablet and slightly greater than the shortest dimension thereof, and means drivingly con- 3 nected'to the rails for causing adjacent rails to reciprocate in opposite directions relative to each other thereby agitating the tablets in the hopper and effecting orientation of the tablets for movement into the troughs.

'4. In a machine for filling containers with tablets, a

'hopper, apparatus for feeding the tablets from said hop- 25v per, said apparatus comprising a plurality of elongated same inclination thereof so that the upper reach thereof forms a bottom for the'troughs, the longitudinal axis of the belt paralleling the longitudinal axis of the troughs,

* m eans for driving the belt so the upper reach thereof I continuously moves upwardly beneath the troughs, each of said rails having a plurality of homaloidal surfaces extending along substantially the entire length thereof and including a pair of vertical surfaces and a plurality of upper inclined surfaces connecting said vertical surfaces,

the adjacent vertical surfaces of adjacent rails being spaced aparta distance less than the longest dimension of each tablet and slightly greater than the shortest dimension thereof, and means drivingly connected to the 'rails for causing adjacent rails to reciprocate in opposite directions relative to each other thereby agitating the tablets" in the hopper and eifecting orientation of the tablets for movement into the troughs. v I 591st machine for filling'i containers with tablets, "a hopper, apparatus for feeding the tablets from said hopper, said apparatus comprising a plurality of elongated parallel rails spaced apart to define a plurality of juxtaposed troughs, said rails extending at an incline from the horizontal and forming the bottom of the hopper, an endless movable belt positioned beneath the rails and at the same inclination thereof so that the upper reach thereof forms a bottom for the troughs, the longitudinal axis of the belt paralleling the longitudinal axis of the troughs, means for driving the belt so the upper reach thereof continuously moves upwardly beneath the troughs, each of said rails having a plurality of homaloid- -a1 surfaces extending along substantially the entire length thereof and including a pair of vertical surfaces on opposite sides thereof, an inclined surface at the top of each rail and first and second bevel surfaces at each side of the inclined surface and connecting same to said vertical surfaces, the adjacent vertical surfaces of adjacent rails being spaced apart a distance less than the longest dimension .of each tablet and slightly greater than the shortest dimension thereof, and means drivingly connected to the rails for causing adjacent rails to reciprocate in opposite directions relative to each other thereby agitating the tablets in the hopper and effecting orientation of the tablets for movement into the troughs. 6. In a machine for filling containers with tablets, a hopper, apparatus for feeding the tablets from said hopper, said apparatus comprising a plurality of elongated parallel railsspaced: apart to (161111623 plurality of juxtaposedtroughs, said rails extending at an incline from the horizontal and forming the bottom of the-hopper,.and

-endless movable belt positioned beneath the rails andat the same inclination thereof so that the upper reach troughs, each of said rails having a plurality of homaloid,

al surfaces extending along substantially the cntirelength thereof and including a pair of vertical surfaces on opposite sidesthereof, an inclined surface atthe top of each rail and first and second bevel surfaces at each side ofthe inclined surface and connecting-same to said ver-.

tical: surfaces, a first edge defined at the juncture of the ,firstbevel surface and the inclined surface, asecond edge defined at the juncture of the second bevel surface and the inclined surface, the adjacent vertical surfaces of adjacent rails being spaced apart a distance less than the longest dimension of each tablet and slightly greater than the shortest dimension thereof, the inclined and I bevel surfaces being arranged sothat the first'bevel surface of one rail faces the second bevel surfaceof an adjacent rail on one side thereof and the distance betweenthe first edge; of said one rail and the second edge of said adjacent rail is slightly less than the longest dimension of a tablet, and; means, drivingly connected to the rails for causing adjacent rails to reciprocate in opposite directions relative to each other thereby agitating the tablets in thehopper and effecting orientation of the tablets for movement into the troughs.

7. In a machine for filling containers with tablets, a hopper, apparatus for feeding the tablets from said hopper, said apparatus comprising a plurality of elongated parallel rails spaced apart to define aplurality-of juxta- Vposed troughs, said rails extending at an incline'from the horizontal and forming the bottom of the hopper, an endless movable belt positioned beneaththe rails and at the same inclination thereof so that the upper-reach,

least, one upper; inclined surface, the adjacent vertical ,surfaces, of adjacent rails being spaced apart a distance less than the longest dimension of each tablet and, slight- 1y, greater than the shortest dimension thereof, means drivingly connected to the rails for causing adjacent rails to reciprocate in opposite directions relative to each other therebyagitatingthe tablets in the hopper and effecting orientation of the tablets for movement into the troughs, afirst baffle plate positioned over and extendrng transverselyacross the rails at a side of the hopper, anda second baffle plate positioned over and extending trans- .verselyacross the rails, at a spaced distance downwardly along the inclined troughs from the first bafiie plate, each of said baffle plates having a series of teeth thereon, each tooth of thejfirst baffle plate extending downwardly into a corresponding trough'toprovide a spacement between the tooth and the movable belt equal to slightly more than twicev the longest dimension .ofone. tablet to-permit a pair of tablets aligned vertically on edge to pass thereunder, each tooth of the second baffle plate extendind downwardly into a corresponding trough to provide aspacement between the tooth and the movable belt equal to slightly more than thelongest dimension of one tablet topermit only a single tablet at a time to pass thereunder.

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